Graphs of Route Difficult Distribution

I've been putting in quite a few hours getting the climbing app ready.  This is lots more work than one would think.  I suspect it will be on the order of 200 - 300 hours when all is said and done.  Layout work is time consuming.  As part of this process, I whipped up an excel sheet to chart first ascent history and index the routes.  Here is a graph of route distribution by crag.  It omits some of the crags with just a couple of routes.

I put 9's and 10a's together.  With the grade softening that is happens in sport areas, I figured the old separation between 9's and 10's isn't as dramatic as it once was.  Without this, I would have to put 6's and 7's together as opposed to grouping 7's and 8's together.  The latter seems like a better fit.  Grouping the 9's and 10a's together also cuts the "10" pile down so comparisons between the number of routes in this pile and those with the other piles are more sensical.

Other ideas are welcome.